SHENZHEN, June 4 (Xinhua) -- Chinese scientists who have fully sequenced the genome of the new E. Coli spreading through Europe said Saturday they found genes in the bacteria that gave it resistance to eight classes of antibiotics.

Researchers with the Beijing Genomics Institute, the world's largest DNA sequencing center, have found genes in the newly identified 0104 strain of E. Coli bacteria that made it resistant to major classes of antibiotics including sulfonamide, cephalothin, penicillin and streptomycin.

This helped explain why doctors in Europe had difficulties in fighting the bug that has killed 18 people and sickened nearly 2,000, BGI's major research arm in Shenzhen said on its website Saturday.

This would help doctors choose right medicines for the treatment, it said.

The researchers are developing a diagnostic kit which will be used to detect the bacteria and prevent the epidemic from spreading further.

The Chinese researchers obtained DNA samples of the bacteria from collaborating scientists in Germany and fully sequenced its genome in three days this week.

They announced on Thursday the E. Coli spreading through Europe was "a new strain of bacteria that is highly infectious and toxic".

The 0104 strain of E. Coli was not previously involved in any E. Coli outbreaks. However, it has 93 percent sequence similarity with the EAEC 55989 E. Coli strain which was isolated in the Central African Republic and known to cause seriously diarrhea, BGI said.

The source of the outbreak is unknown, but scientists say it is highly likely to have originated in contaminated vegetables or salad in Germany.